Problem: Add.
There are many ways to solve this problem. Let's see two ways we can solve it. Place value table Let's line up the numbers by their decimal places. Tens Ones $.$ Tenths Hundredths $7$ ${1}$ $.$ ${8}$ $0$ $7$ $.$ ${6}$ $9$ Now, let's add each place value column. Tens Ones $.$ Tenths Hundredths $7$ $\overset{1}{{1}}$ $.$ ${8}$ $0$ $+$ $7$ $.$ ${6}$ $9$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $\underline{~~~~}$ $7$ $9$ $.$ $4$ $9$ Decomposing the numbers We can group the whole numbers together and the decimals together. $\begin{aligned} &({71}+ 7) + ({0.80} + {0.69})\\\\ &=78 + {1.49}\\\\ &=79.49 \end{aligned}$ $79.49 = 71.8 + 7.69$